An example of conventional folding communication terminals is shown in FIG. 14. This folding communication terminal includes a first enclosure 101, a second enclosure 102 and a hinge 103 connecting the first and second enclosures 101, 102 to each other so that they are foldable. In this folding communication terminal, generally, the first enclosure 101 is provided with an antenna 104 as shown in FIG. 14(A), or otherwise the second enclosure 102 is provided with the antenna 104 as shown in FIG. 14(B).
Further, various antennas to be used in this folding communication terminal are known. For example, a pull-out whip antenna has the characteristic of a relatively wide band in the frequency band, but it is obstructive when pulled out. Further, a helical antenna is narrow in the frequency band and also protrusive so that it is not excellent in portability. On the other hand, although incorporated antennas such as an inverted F antenna are also known, they are also narrow in the frequency band.
In order to obviate such an inconvenience, a communication terminal has been developed in which as shown in FIG. 15, electric power is supplied from the second enclosure 102 equipped with a wireless portion 105 having a transmission/reception circuit to a plate-like element 107 incorporated within the first enclosure 101 through a power supply line or feeder 106 and the plate-like element 107 is used as the antenna (see for example Patent Reference 1).
Patent Reference 1: JP-A-2001-136255 (Page 5, FIG. 1)